130 pupils went for a spelling test and 56 of them achieved Gold certificates.
35 of the boys and
15 of the girls achieved Gold certificates. How many boys did not achieve Gold certificates?
| Girls |
Boys |
| 5 u |
5 p |
Achieved
Gold |
Did not achieve
Gold |
Achieved
Gold |
Did not achieve
Gold |
| 3 u |
2 u |
1 p |
4 p |
Number of pupils who did not achieve Gold certificates
= 130 - 56
= 74
3 u + 1 p = 56
1 p = 56 - 3 u --- (1)
2 u + 4 p = 74
4 p = 74 - 2 u --- (2)
Make p the same.
(1)
x44 p = 224 - 12 u --- (3)
(2) = (3)
74 - 2 u = 224 - 12 u
12 u - 2 u = 224 - 74
10 u = 150
1 u = 150 ÷ 10 = 15
Number of girls who achieved Gold certificates
= 3 u
= 3 x 15
= 45
Number of boys who achieved Gold certificates
= 56 - 45
= 11
Answer(s): 11
